code: def save(file, arr):
      """Save an array to a binary file in NumPy ``.npy`` format.
  
      Parameters
      ----------
      file : str
          File or filename to which the data is saved.  If file is a file-object,
          then the filename is unchanged.
      arr : ndarray
          Array data to be saved. Sparse formats are not supported. Please use
          savez function to save sparse arrays.
  
      See Also
      --------
      savez : Save several arrays into a ``.npz`` archive
  
      Notes
      -----
      For a description of the ``.npy`` format, see :py:mod:`numpy.lib.format`.
      """
      if not isinstance(arr, NDArray):
          raise ValueError("data needs to either be a MXNet ndarray")
      arr = [arr]
      keys = None
      handles = c_handle_array(arr)
      check_call(
          _LIB.MXNDArraySave(
              c_str(file), mx_uint(len(handles)), handles, keys
          )
      )
  
file_path: mxnet/python/mxnet/numpy_extension/utils.py
imports: import ctypes
  from ..util import is_np_array, is_np_shape
  from ..base import _LIB, check_call, string_types, c_str_array
  from ..base import c_handle_array, c_str, mx_uint, NDArrayHandle, py_str
  from ..dlpack import ndarray_to_dlpack_for_read, ndarray_to_dlpack_for_write
  from ..dlpack import ndarray_from_dlpack, ndarray_from_numpy
  from ..numpy import ndarray, array
  from ..ndarray import NDArray
label_desc: Use image node_id 1 for calling a global function with example usage: save(file, arr) without return types